A mathematical model for predicting putative association between E2/T ratio and the development of benign prostate hyperplasia in rats

Benign prostatic hyperplasia (BPH) develops more likely with increasing age and changing serum concentrations of circulating estradiol (E2) and/or testosterone (T). In this study, we explored the relationship between serum E2/T ratio and BPH risk in rats by fitting a mathematical model. A total of 176 rats were randomized to one of the following treatment groups: normal control, castrated control, and 20 more groups of castrated animals treated with increasing dose combinations of T and E2, once daily for 30 days. Serial blood samples were obtained to determine serum T and E2 levels by magnetic bead enzyme-linked immunosorbent assay. Prostate tissue was taken to measure prostate volume. MATLAB software was used to simulate the relationship between prostate/body weight ratio (PBR) and E2/T ratio with a mathematical equation. The values of PBR, E2 and T in the treatment groups were significantly higher than those in the control groups. Stepwise regression showed that PBR was a function of E2 and T. PBR = –0.1782 + 0.0081 E2 + 0.063 T – 0.6 × 10–5 E22 – 0.28 × 10–3 T2. E2/T ratio change may be one of the risk factors for PBR, which is associated with the development of BPH. Summary Sentence E2 /T ratio change may be one of the risk factors for PBR, which is associated with the development of BPH.